Induction linear traction motor for monorail systems



FIPSEUZ XR Fri/5471041 [72] Inventors Georgy lgnatievich Izhelya ulitsaMalopodvalnaya, 14. kv. 13; Konstantin Alexeevich Bykov, ulitsaStreletskaya, l4, kv. 2; Boris Sokratovich Veneraki, ulitsa Gorkogo,155, kv. 28; Alexandr lvanovich Vishnikin, ulitsa Belorusskaya, l, kv.l7; Vladimir Andreevich Mishakin, ulitsa Selskokhozyaistvennaya,7/9, kv.l9; Sergei Alexeevich Rebrov, ulitsa Nikolsko- Botanicheskaya, l4, kv.20; ltskhok Avrumovich Spektor, ulitsa Muromskaya,

3, kv. l; Alexandr Grigorievich Shapovalenko, ulitsa Zatonskogo, /41,

kv. 25, Kiev, U.S.S.R. [21 Appl. No. 704,836 [22] Filed Feb. 12, 1968Patented Dec. 15, 1970 [54] INDUCTION LINEAR TRACTION MOTOR FOR MONORAILSYSTEMS 3 Claims, 5 Drawing Figs.

[52] US. Cl 104/148, 310/12 v1! III II I! 1 III I II II II ll 11 I I]III! 'IIIIIIII/l 1/!" [51 Int. Cl 860m 5/00, H02k 41/02 Field ofSearch318/; 7 310/l2,l3;l04/148LM [56] References Cited UNITED STATES PATENTS2,337,430 l2/l943 Trombetta 310/13 2,666,879 1/1954 Godsey,Jr. etal.l04/l48(LM)(UX) Primary Examiner-Arthur L. La Point AssistantExaminerGeorge H. Libman Attorney-Waters, Roditi, Schwartz & NissenABSTRACT: An induction linear traction motor for monorail systemswherein a running rail is used as the rotor, whereas stators embrace therunning rail on both sides thereof, the magnetic cores of each statorbeing divided lengthwise into sections interconnected by means ofarticulated joints capable of providing relative turning movement ofadjacent sections during passage of the stators along a curvilinearsection of the rail with a small radius of curvature.

/lr 1/ 111/ II I III! II II I! I sum 2 or 2 PATENTED nun 5 I970 INDUTINLENEAR TRACTEON MOTOR FOR MONORAIL SYSTEMS The present invention relatesto induction linear traction 'motors employed on monorail systems.

Conventional designs of induction linear traction motors wherein therunning rail is used as the rotor, employ unrolled statorsv capable ofembracing said rail on both sides, which are provided with a rigidstructure of magnetic cores.

As is known, the length of an unrolled stator as viewed in the directionof movement with constant motor power supply frequency increases withincrease of the motor speed. Therefore the total length of the statormay be of the order of 1.5 to 2 m. and more, which hinders thenegotiation of the motor along curves due to the fact that the air gapbetween the stator magnetic core and the running rail increases on theinner side of the track curvature, whereas that on the outer sidedecreases. Variation of the air gap magnitude in movement results inimpaired traction and power performance thereof. To provide negotiationof curves by the motor without significant variation of the air gap inthe case of a rigid structure of the stator magnetic core, it isnecessary to increase considerably the rated magnitude of said gapwhich, in turn, will lead to impaired traction and power performance ofthe motor.

Especially abrupt variations of the air gap occur when small radii ofcurvature are passed (with the stator magnetic core lengths of 1.5 to 2m. for radii of curvature of 50 to 100 m.), for example, on shuntingtrack sections, turnouts, when the monorail lines are built in populatedareas, etc. This may lead to touching of the running rail by the statorcore.

The primary object of the present invention is to provide for the motorto pass small radii of monorail curvature (from to m.) with practicallyconstant air gap between the stator magnetic cores which facilitate theimproving of traction and power performance of the motor.

The object of the invention is accomplished by an arrangement whereinthe magnetic cores of each stator are divided lengthwise in thedirection of movement into separate sections which are connected withone another through articulated joints capable of providing for anysection on the track our vilinear sections with small radius thepossibility to turn with respect to one another.

It is expedient that each joint be made as a bushing or sleeve enteringa hole arranged in protrusions of adjacent sections of the magneticcore. Moreover, it is advantageous that the articulated joint ofadjacent magnetic core sections be made as a stack of overlappinglaminations so as to retain the stator permeance.

The invention will be more apparent from a consideration of an examplaryembodiment thereof with reference to the appended drawings, wherein:

FIG. 1 is a plan view of the arrangement of magnetic core sections ofthe unrolled stators of the motor with respect to the running monorail;

FIG. 2 is a cross section of the unrolled stator through the magneticcore articulated joint;

H6. 3 is a plan view of a magnetic core articulated joint; and

FIGS. 4 and 5 show the arrangement of laminations of stator sections forstacked magnetic cores.

As is seen in FIG. l, magnetic cores 1 of the unrolled stators in aninduction linear traction motor for monorail systems are arranged onboth sides of a rectangular running rail 2 which serves as the rotor ofthe motor. To enable the motor to pass monorail sections with smallradii of curvatures, the magnetic cores 1 are made of separate sections3 connected with one another by magnetic joints. The split of theseparate sections 3 of the magnetic core 1 is made in the middle portionof the stator slots. Therefore the presence of gaps between the separatesections of the magnetic cores does not affect the stator teethpermeance.

A joint is essentially constituted as a steel polished bushing or sleeve4 which is fitted in holes stamped in protrusions of laminations 5(FIGS. 2 and 3) of the ma netic cores ll. The laminations 5 of themagnetic core 1 are c amped by means of a nut 6 and a washer 7. Insidethe bushing or sleeve #1 provision is made for pins capable ofconnecting the magnetic core sections to the motor body (not shown inthe drawing).

A specific feature of the articulated joint of the sections is to keepconstant the permeance of the stator core in the place of thearticulated joint and thus the latter is made of overlappinglaminations. The arrangement or laminations is shown in FIGS. 4- and 5.Such a design of the joint allows efiective manufacture not requiringthat the air gap 6, (FIGS. 2 and 3) be small. Practically, said air gapmay be assumed equal to l to 2 mm.

If the joint is not made laminated, the entire magnetic flux in thestator core is able to pass through said gap which would considerablyincrease the magnetizing current of the motor.

In the proposed joint, the working gap for a magnetic flux of the statorcore is air gap 5 (FiG. 2) between the planes of laminations 5 of thestator stack which may be a small fraction of a millimeter (practicallysaid gap may be assumed equal to the insulation layer thickness of thelaminations 5 Therefore the reluctance of a laminated joint is severalhundred times smaller than that of a nonstacked joint and does notpractically affect the total reluctance of the stator core.

To prevent damaging the winding in the stator slots at the places wherethe magnetic core sections are articulated, rigid plastic bushings orsleeves 8 (FIG. 3) are titted into said slots said bushings or sleevesserving as slot insulation of the stator winding.

With actual curvature radii of the monorail running rail, the angle ofturn of one magnetic core section of the unrolled stator with respect tothe other section is only 1 or 2, therefore the rigid bushing or sleeve3 freely located in the slot will reliably protect the winding fromdamage.

Apart from its direct application, i.e.' as a traction electric drivefor rolling stock of monorail systems the present invention may beemployed in other transport and hoisting mechanisms and devices wheresmall radii of curvature of the running rail occur.

We claim:

1. An induction linear traction motor for monorail systems comprising arunning rail as the rotor, stators embracing said running rail on bothsides, said stators including magnetic cores divided lengthwise intosections, and means interconnecting said sections including articulatedjoints capable of providing relative turning movement of said sectionsto enable travel along a curvilinear rail with a small radius ofcurvature.

2. A motor as claimed in claim 1 wherein each said articulated joint ofsaid stator sections comprises a bushing engaged in aligned holesprovided in protrusions of adjacent sections of the stator magneticcore.

3. A motor as claimed in claim l wherein said magnetic cores of adjacentsections are constituted as overlapping laminations which allow forvarying stator permeance at the places where said articulated joints ofsaid sections are located.

